1. Field of the Invention
The present invention relates to silver halide color photographic sensitive materials, particularly, to silver halide color photographic materials having improved color reproduction which are not affected by differences in ultraviolet absorption characteristics of a camera lens. Further, the present invention relates to a method of improving variations in color balance caused by differences in the ultraviolet ray absorption of a camera lens.
2. Description of the Prior Art
In available cameras, lenses which are coated with an ultraviolet ray absorbing agent or lenses which are not coated with an ultraviolet ray absorbing agent are in use.
When an object is photographed using these two kinds of lenses under the same conditions and the silver halide photographic sensitive materials thus exposed are processed under the same conditions, the resulting photographic images generally have different color tones. This phenomenon results from the fact that the percent transmission of ultraviolet rays of the lens and the wavelength range of light absorbed by the lens vary depending on the presence or absence of an ultraviolet ray absorbing agent.
Hitherto, many compounds have been known as ultraviolet ray absorbing agents. However, there are only a few compounds which satisfy the following three characteristics:
1. They effectively absorb ultraviolet rays of 300 to 400 m.mu. and do not absorb visible rays of above 420 m.mu.;
2. They do not change in color upon development;
3. They do not have a harmful influence upon photographic sensitive materials at preparation, during storage or at development thereof.
Many available ultraviolet ray absorbing agents run out or discolor during the development processing and some of them have a harmful influence on photographic sensitive emulsions. Compounds analogous to the compounds of the present invention are described in U.S. Pat. No. 3,278,448. However, they have insufficient absorption in the wavelength range of 300 to 400 nm, and, consequently, they do not satisfy the above described absorption characteristics or emulsification or dispersion thereof is unsatisfactorily carried out.